Automotive door ring system

Abstract

A motor vehicle door ring system comprises a door ring 2 with an A-pillar section 3, a B-pillar section 4, a roof section 5, and a sill section 5. The door ring 2 is hot-formed and press-hardened in one piece from a base plate of uniform material and wall thickness. At least one first region 7 of the door ring 2 is provided with a reinforcing plate 8. At least one second region 9 of the door ring 2 has a ductility-influenced zone 10 formed by holes 11.

Description

[0001] The invention relates to a motor vehicle door ring system with a door ring made of a press-hardenable steel material.

[0002] EP 1 172 454 B1 discloses a side wall of a motor vehicle comprising a sill extending along the lower section, a roof frame section, and pillars extending between the sill and the roof frame section, wherein the sill, the pillars, and the roof frame section are manufactured in one piece from a correspondingly sized base plate. The base plate consists of a steel material with a yield strength of 500 MPa or less, with sections of the resulting side wall being partially hardened. This is intended to allow for the use of a thinner base plate overall and thus reduce weight.

[0003] A method for manufacturing a motor vehicle structural component and in particular a door ring for a motor vehicle is considered state of the art according to DE 11 2017 003 027 T5.

[0004] Starting from the prior art, the invention is based on the objective of providing a functionally improved motor vehicle door ring system with a crash performance designed to withstand the load.

[0005] The solution to this problem consists of a motor vehicle door ring system according to claim 1.

[0006] Advantageous embodiments and further developments of the motor vehicle door ring system according to the invention are the subject of the dependent claims.

[0007] Embodiments and modifications of features of the door ring system, which individually or in combination make the invention technically advantageous, also result from the description and the accompanying drawings.

[0008] The vehicle door ring system comprises a door ring that includes an A-pillar section, a B-pillar section, a roof section, and a sill section. The term "section" is used hereafter to refer to an A-pillar section, a B-pillar section, a roof section, or a sill section. The door ring is made of a press-hardenable steel material, in particular a manganese-boron alloyed steel material, preferably a steel material designated 22MnB5 or 36MnB5.

[0009] According to the invention, the door ring is hot-formed and press-hardened in one piece from a base plate of uniform material and wall thickness. At least one first area of ​​the door ring is provided with a reinforcing sheet, a so-called patch. At least one second area of ​​the door ring, distinct from the first, has a ductility influence zone formed by holes.

[0010] The door ring system offers manufacturing advantages. Areas of the door ring that must absorb impact energy and other areas that should remain rigid and inflexible are coordinated, with the design and arrangement of the at least one reinforcing plate and the at least one ductility-influenced zone complementing each other synergistically. The door ring itself is manufactured from a single-piece, uniform base plate of consistent wall thickness. Before hot forming and press hardening, the base plate is provided with at least one reinforcing plate in one area. Similarly, holes or a hole pattern are created in the base plate, forming a ductility-influenced zone in one area of ​​the finished component. The base plate thus prepared is then hot formed and press hardened in a press tool. After press hardening, the door ring exhibits strengths exceeding 1.The door ring has a strength of 200 MPa, in particular between 1,300 MPa and 2,000 MPa. The strength, especially the bending strength, is further increased in a first area by at least one reinforcing plate, while in at least another second area, the ductility-influenced zone, the compliance and deformation behavior are controlled.

[0011] The automotive door ring system according to the invention exhibits highly efficient crash performance despite its weight-optimized design. In areas where increased bending stiffness is required, the door ring system is further reinforced and stiffened by at least one reinforcing plate. The additional ductility influence zone, formed by holes in the wall of the door ring, leads to the equalization and distribution of tensile stress loads. The arrangement and geometry of the holes divide the load into load paths or stress paths. Within the ductility influence zone, the door ring deforms plastically by bending. The tendency to crack is reduced. In particular, an incipient crack can be interrupted or diverted by adjacent holes and their specific position and geometry, so that the crack remains outside of failure-critical areas of the door ring.

[0012] The reinforcement plate and / or the ductility influence zone can be arranged in a horizontally oriented section, in particular the A-pillar section, of the door ring.

[0013] Furthermore, the reinforcement plate and / or the ductility influence zone can be provided in the B-pillar section of the door ring.

[0014] Another advantageous embodiment provides that the reinforcing plate is arranged in a transition area between a horizontally oriented section and a vertically oriented section of the door ring, in particular in an arc section between a roof section and a B-pillar section or a roof section and an A-pillar section. A reinforcing plate can also be provided between a sill section and a B-pillar section or an A-pillar section.

[0015] The ductility influence zone can also be located in a transition area between a horizontally oriented section and a vertically oriented section, particularly in an arc section.

[0016] The terms "horizontal" and "vertical" refer to the installation position of the door ring or the vehicle door ring system within a motor vehicle. Horizontal means that the section extends along the x-axis of the vehicle, i.e., the vehicle's longitudinal axis. Vertical means that the section extends along the z-axis of the vehicle, i.e., the vehicle's vertical axis.

[0017] In a further advantageous embodiment, two ductility influence zones are provided in a section of the door ring, particularly the sill section, spaced apart from each other. Within the sill section, the two ductility influence zones are spaced apart along the x-axis. Furthermore, two ductility influence zones can be arranged one above the other in the sill section, spaced apart along the z-axis. In this embodiment, one ductility influence zone is formed in a lower side leg and one ductility influence zone in an upper side leg of the sill section.

[0018] It is also considered advantageous if two ductility influence zones arranged vertically apart from each other in a B-pillar section of the door ring are provided, wherein the area fraction of the holes in the lower ductility influence zone is larger than the area fraction of the holes in the upper ductility influence zone.

[0019] One section of the door ring has a U-shaped cross-section. This section has a web and two side legs. The reinforcing plate lies flat against the web and extends between the two side legs. The reinforcing plate may have lateral flanges oriented parallel to the side legs.

[0020] In another area of ​​a section of the door ring, the ductility influence zone is formed. This section also has a U-shaped cross-section with a web and two side legs. The ductility influence zone is located within the web.

[0021] An alternative design provides that, in a section configured in a U-shape with a web and two side legs, the ductility influence zone is only provided in one side leg.

[0022] The sill section can also be configured in a U-shape in cross-section, with a web and two side legs. Each side leg contains a ductility influence zone, and these zones are arranged opposite each other. This means that the ductility influence zones are aligned vertically along the z-axis. The hole pattern in the ductility influence zones can be identical or different. An identical hole pattern can be advantageous for vehicles whose sill section, when installed, is fully impacted by a reference test barrier or pole. Conversely, it can be advantageous to design the hole pattern in the upper sill section with fewer or smaller holes, or with a smaller area of ​​holes, compared to the hole pattern in the opposite lower side leg, if the vehicle's center of gravity and the installation position of the sill section are relevant, such as...The height of SUVs or off-road vehicles is relatively high, so the test barrier or test post hits the sill section off-center and further up.

[0023] In a section, i.e., an A-pillar section, a B-pillar section, a roof section, or a sill section, this section can be configured in a U-shape, either entirely or at least over part of its length. The U-shaped section has a web and two side legs. One aspect of the invention provides that the transition from a side leg to the web is unperforated, i.e., a continuous transition without interruption by a hole is provided.

[0024] Furthermore, it is advantageous for a section of the U-shaped door ring to be closed by a strike plate. The strike plate can be flat, acting as a tension strut, but in the case of the sill and A-pillar sections, it is preferably profiled.

[0025] The ductility behavior in a ductility-influenced zone can be further influenced by providing at least one groove within the zone, with the holes extending into the groove. In this configuration, the ductility-influenced zone has a groove, i.e., a channel-shaped material projection or depression, with holes provided in the groove itself.

[0026] An advantageous embodiment incorporates an X-shaped corrugation. This corrugation(s) within the ductility influence zone allows for increased energy absorption compared to similar, but unstiffened, cross-sectional profiles.

[0027] A particularly advantageous embodiment of the invention, especially with regard to electric vehicles, provides that the sill section extends parallel to a battery box located in the floor area of ​​the vehicle and is positioned in front of the battery box at the same height as the battery box. The battery box represents an additional rigid crash structure below the vehicle floor, which is preferably attached directly to the sill section. To optimally protect the batteries in a side impact—especially against high peak forces—the sill section of the door ring designed according to the invention can have one or more ductility influence zones with holes or a hole pattern that achieve initial energy absorption.

[0028] It is also advantageous if the base plate and the reinforcement plate are provided with a corrosion protection layer on at least one side.

[0029] In this context, an advantageous aspect is that the corrosion protection layer is an alloy layer containing aluminum and silicon and is at least 20 µm thick. On top of the aluminum and silicon alloy layer, a further layer containing an element from the zinc, nickel, or manganese group can be applied to improve long-term corrosion protection or to improve the absorption of thermal radiation and thus the heating rate during furnace heating in the hot forming process.

[0030] The invention is described in more detail below with reference to exemplary embodiments illustrated in the drawings. The drawings show: Fig. 1 a first embodiment of a motor vehicle door ring system in a side view; Fig. 2 a section through the representation of the Fig. 1 along line AA; Fig. 3 a section through the representation of the Fig. 1 along line BB; Fig. 4 a second embodiment of a motor vehicle door ring system in a side view; Fig. 5 a third embodiment of a motor vehicle door ring system in a side view; Fig. 6 a section through the representation of Fig. 5 along line AA; Fig. 7 a section through the representation of the Fig. 5 along line BB; Fig. 8 Another embodiment of a motor vehicle door ring system in a side view; Fig. 9 a section through the representation of the Fig. 8 along line AA; Fig. 10 a side panel of an electric motor vehicle with a motor vehicle door ring system in a side view; Fig. Figure 11 technically schematically shows a highly simplified view of the battery box area of ​​an electric vehicle; Fig. Figure 12 also schematically and technically simplified a cross-section through the bottom-side sill area of ​​the motor vehicle door ring system according to the representation of Fig. 10; Fig. 13 Another embodiment of a motor vehicle door ring system in a side view; Fig. 14 a side view of the B-pillar section of the motor vehicle door ring system according to the illustration of Fig. 13; Fig. 15 a section through the representation of the Fig. 13 along line AA; Fig. 16 a section through the representation of the Fig. 13 along line BB and Fig. 17 a section of a B-pillar in the area of ​​the column base.

[0031] In the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16 to Fig. 17. The same reference symbols are used for identical or functionally equivalent components or component parts.

[0032] Terms such as "top" and "bottom," "horizontal" and "vertical," or "longitudinal" and "transverse," "roof section," "roof-side," "sill section," "sill-side," "A-pillar," "A-pillar-side," "B-pillar," and "B-pillar-side" refer to the installation position of the vehicle door ring system within a vehicle body. Horizontally oriented means that a section of the door ring extends essentially along the x-axis, i.e., the vehicle's longitudinal axis. Vertically oriented means that a section of the door ring extends essentially along the z-axis, i.e., the vehicle's vertical axis. The y-axis corresponds to the vehicle's transverse axis.

[0033] The Fig. 1, Fig. 4, Fig. Figures 5, 8, 10 and 13 each show a motor vehicle door ring system 1 in a side view.

[0034] The vehicle door ring system 1 comprises a door ring 2, which includes an A-pillar section 3, a B-pillar section 4, a roof section 5, and a sill section 6. The A-pillar section 3 and the B-pillar section 4 are oriented vertically within the door ring 2. The roof section 5 and the sill section 6 run horizontally and extend from their basic orientation along the vehicle's longitudinal axis (x-axis).

[0035] The door ring 2 is hot-formed and press-hardened in one piece from a base plate of uniform wall thickness made of a single material. The base plate consists of a press-hardenable steel material, in particular a manganese-boron alloy steel. A first region 7 of the door ring 2 is provided with a reinforcing plate 8. A second region 9 of the door ring 2 has a ductility-influenced zone 10. The ductility-influenced zone 10 is formed by a pattern of holes 11.

[0036] For the production of the automotive door ring system 1, a pre-fabricated base plate made of press-hardenable steel is provided. This corresponds to the development of the door ring 2 to be produced, with a material specification to be taken into account for forming purposes. The base plate has a door cutout adapted to the later door opening. The base plate, which is flat in its initial state, is provided with one or more reinforcing plates 8 in certain areas. Furthermore, a pattern of holes is created in other areas. The base plate, provided with holes and at least one reinforcing plate, is hot-formed and press-hardened in a press tool.

[0037] The base plate and the reinforcing plate 8 can have a corrosion protection layer on at least one side. The base coating providing corrosion protection is applied before hot forming and press hardening. The corrosion protection layer that forms during press hardening is, in particular, an alloy layer containing aluminum and silicon and has a thickness of 20 µm.

[0038] In the case of the motor vehicle door ring system 1, as in the Fig. As shown in Figure 1, the door ring 2 in the B-pillar section 4 has a first area 7, which is stiffened by a reinforcing plate 8. Below the first area 7, and at a distance from the first area 7, is a second area 9, in which the ductility influence zone 10 with the holes 11 is formed. Furthermore, a third area 7a is provided with a reinforcing plate 8a. The reinforcing plate 8a is provided in a transition area between the horizontally oriented roof section 5 and the A-pillar section 3, and specifically in the curved section 16.

[0039] A first area 7 of the door ring 2 and a second area 9 of the door ring 2 means that these are spatially distinct areas 7 and 9 of the door ring 2 in sections 3, 4, 5, and 6. Consequently, an area subsequently designated as a third or fourth area within a section 3 to 6 can also be a second area 9 distinct from the first area 7.

[0040] The motor vehicle door ring system 1 according to the illustration of Fig. 4 corresponds to the one based on the Fig. The system described in section 1. Additionally, a fourth area 12 with a ductility influence zone 14 is provided. The ductility influence zone 11 is formed by a number of holes 15. The fourth area 12 with the ductility influence zone 14 is located at the upper end of the B-pillar section 4 below the transition 13 to the roof section 5. The two ductility influence zones 10 and 14 are arranged at a vertical distance v1 from each other. This design causes the B-pillar section 4 to bend off-center. The area fraction of the holes 11 in the lower ductility influence zone 10 is larger than the area fraction of the holes 15 in the upper ductility influence zone 14.

[0041] In the case of the motor vehicle door ring system 1, as shown in the illustration of Fig. 5. A first area 7 with a reinforcing plate 8 is located in the B-pillar section 4. Below the first area 7, a second area 9 with a ductility influence zone 10 formed by holes 11 is provided. This design corresponds to the embodiment of Fig. 1.

[0042] A further ductility influence zone 17 is provided in roof section 5. The ductility influence zone 17 is formed by a pattern of holes 18 arranged at intervals along the longitudinal direction of roof section 5.

[0043] The representations of Fig. 6 and Fig. Figure 7 shows the cross-section of the B-column section 4 along the intersection line AA and BB.

[0044] The B-pillar section 4 has a U-shaped cross-section and comprises a web 19 and two side legs 20, 21. Outwardly directed flange sections 22 adjoin the side legs 20, 21. The reinforcing plate 8 is provided in area 7. The reinforcing plate 8 is also U-shaped. It abuts the web 19 and extends between the side legs 20, 21. Along its length, the reinforcing plate 8 has side sections 23 that extend parallel to the side legs 20, 21 of the B-pillar section 4.

[0045] The B-pillar section 4 is closed by a strike plate 24. With respect to the installation position of the vehicle door ring system 1 in a vehicle, the strike plate 24 is located on the inside of the door ring 2 or the B-pillar section 4. The strike plate 24 is positioned at a distance from the web 19 of the B-pillar section 4. The strike plate 24 closes the U-shaped cross-section of the B-pillar section 4 on the inside.

[0046] The B-pillar section 4 has a web groove 25 which extends in the z-axis at the door opening-side transition 26 from the web 19 to the side leg 20 there.

[0047] The Fig. Figure 6 illustrates that the reinforcing plate 8 is also configured accordingly and has a web groove 27.

[0048] In the case of the motor vehicle door ring system 1, as shown in the illustration of Fig. In the ductility influence zone 10, a groove 28 is formed. This groove is an X-shaped depression formed by an X-shaped depression in the wall of the B-column section 4. It can be seen that the holes 11 of the ductility influence zone 10 continue into the groove 28. Consequently, holes 11 are formed in the X-shaped groove 28.

[0049] Based on the Fig. 10, Fig. 11 and Fig. Figure 12 describes a motor vehicle door ring system 1 for an electric vehicle. A battery box 29 is shown in a highly simplified and schematic form. The sill section 6 extends parallel to the battery box 29 in front of it at the same height. The battery box 29 has very high rigidity. The sill section 6 has two ductility influence zones 10, 14, formed by holes 11 and 15, respectively. The holes 11 of the ductility influence zone 10 are arranged in side legs 20, 21 of the U-shaped sill section 6. Holes 11 are provided in the upper side leg 20 and holes 15 in the lower side leg 21. The two ductility influence zones 10, 14 in the sill section 6 are positioned one above the other with a vertical distance v2 along the z-axis.

[0050] Arrow P indicates the direction of impact in a side impact.

[0051] The ductility influence zone 14 in the lower side leg 21 of the sill section 6 extends over a length in the Fig. 10 illustrated length section l. The lower side leg 21 can also be provided with a continuous hole pattern of holes 15.

[0052] Another embodiment of a motor vehicle door ring system 1 is shown in the Fig. 13, Fig. 14, Fig. 15 to Fig. 16.

[0053] A first area 7 of the B-pillar section 4 is reinforced by a reinforcing plate 8. In a second area 9, the B-pillar section 4 has a ductility influence zone 10 formed by holes 11. The B-pillar section 4 has a U-shaped cross-section. The reinforcing plate 8 also has a U-shaped cross-section. Furthermore, the B-pillar section 4 is closed on the inside by a closing plate 24. The holes 11 of the ductility influence zone 10 are located in the web 19 and in the side legs 20, 21 of the B-pillar section 4. In contrast to the previous embodiments, the holes here extend over a larger portion—preferably between 10% and 20%—of the length of the B-pillar section and have up to six rows of holes. The energy absorption capacity is particularly high due to strong, targeted, local stretching in this ductility influence zone 10.The transitions 30 from the web 19 to the side legs 20, 21 along the standing longitudinal edges are unperforated, so that a controlled buckling also takes place in the ductility influence zone, but either under again increased deformation work or energy absorption or in combination or to compensate for two small trigger beads 31 along the longitudinal edges 32, as in . Fig. 17 are shown in detail.

[0054] Furthermore, one can see in the Fig. 13 a fourth area 12 in the upper side leg 20 of the sill section 6, in which a ductility influence zone 17 formed by holes 18 is provided. A fifth area 33 opposite this, with a further ductility influence zone 17 in a partial length x of the sill section 6 in the lower side leg 21, is indicated by a curved bracket. Reference symbol: 1 Motor vehicle door ring system 2 door rings 3 A-pillar section 4 B-pillar section 5 Roof section 6 Sill section Area 7 7a area 8 Reinforcing plates 8a Reinforcing plate 9 area 10 Ductility influence zone 11 holes 12 area 13 Transition 14 Ductility influence zone 15 holes 16 arc section 17 Ductility influence zone 18 holes 19 Bridge 20 side thighs 21 Side thigh 22 Flange section Section 23 24 strike plate 25 ribbed 26 Transition 27 Bridge bead 28 groove 29 Battery box 30 Transition 31 Trigger bead 32 Long edge 33 Area l length section P arrow v1 vertical distance v2 vertical distance x Part length

Claims

[1] Motor vehicle door ring system comprising a door ring (2) comprising an A-pillar section (3), a B-pillar section (4), a roof section (5) and a sill section (6), formed from a press-hardenable steel material, characterized by , that the door ring (2) is hot-formed and press-hardened in one piece from a base plate of uniform material and wall thickness, and that at least a first area (7) of the door ring (2) is provided with a reinforcing plate (8), and that at least a second area (9) of the door ring (2) has a ductility influence zone (10, 14) formed by holes (11, 15). [2] Motor vehicle door ring system according to claim 1, characterized by , that the reinforcement plate (8) and / or the ductility influence zone (10, 14) is arranged in a horizontally oriented section of the door ring (2). [3] Motor vehicle door ring system according to claim 1 or 2, characterized by, that the reinforcement plate (8) and / or the ductility influence zone (10, 14) is arranged in the B-pillar section (4) of the door ring (2). [4] Motor vehicle door ring system according to one of claims 1 to 3, characterized by , that the reinforcing plate (8) is arranged in a transition area between a horizontally oriented section and a vertically oriented section. [5] Motor vehicle door ring system according to one of claims 1 to 3, characterized by , that the ductility influence zone (10, 14) is located in a transition area between a horizontally oriented section and a vertically oriented section. [6] Motor vehicle door ring system according to any one of claims 1 to 5, characterized by , that in a section there are two ductility influence zones (10, 14) arranged at a distance from each other. [7] Motor vehicle door ring system according to any one of claims 1 to 6, characterized by, that in a B-pillar section (4) of the door ring (2) there are two ductility influence zones (10, 14) arranged at a vertical distance from each other, wherein the area fraction of the holes (15) in the lower ductility influence zone (14) is larger than the area fraction of the holes (11) in the upper ductility influence zone (10). [8] Motor vehicle door ring system according to any one of claims 1 to 7, characterized by , that a section of the door ring (2) is configured in a U-shape in cross-section with a web (19) and two side legs (20, 21), wherein the reinforcing plate (8) rests against the web (19) and extends between the two side legs (20, 21). [9] Motor vehicle door ring system according to any one of claims 1 to 8, characterized by , that a section of the door ring (2) is configured in a U-shape in cross-section with a web (19) and two side legs (20, 21), wherein the ductility influence zone (10, 14) is present in the web (19). [10] Motor vehicle door ring system according to any one of claims 1 to 9, characterized by , that a section of the door ring (2) is configured in a U-shape in cross-section with a web (19) and two side legs (20, 21), wherein the ductility influence zone (10, 14) is only present in one side leg (20, 21). [11] Motor vehicle door ring system according to any one of claims 1 to 10, characterized by , that the sill section (6) is configured in a U-shape in cross-section with a web (19) and two side legs (20, 21), wherein a ductility influence zone (10, 14) is present in each of the side legs (20, 21) and the ductility influence zones (10, 14) are arranged opposite each other. [12] Motor vehicle door ring system according to claims 8 to 11, characterized by , that the transition (30) from a side leg (20, 21) to the bridge (19) is unperforated. [13] Motor vehicle door ring system according to any one of claims 1 to 12, characterized by, that at least one section of the door ring (2) is closed by a strike plate (24). [14] Motor vehicle door ring system according to any one of claims 1 to 13, characterized by , that within the ductility influence zone (10) at least one groove (28) is present, with the holes (11) continuing into the groove (28). [15] Motor vehicle door ring system according to claim 14, characterized by , that an X-shaped groove (28) is present. [16] Motor vehicle door ring system according to any one of claims 1 to 15, characterized by , that the sill section (6) extends parallel to a battery box (29) and is arranged in front of the battery box (29) at the same height level as the battery box (29). [17] Motor vehicle door ring system according to any one of claims 1 to 16, characterized by , that the base plate and the reinforcement plate (8) are provided with a corrosion protection layer on at least one side. [18] Motor vehicle door ring system according to claim 17, characterized by that the corrosion protection layer is an alloy layer containing aluminium and silicon and is at least 20 µm thick.

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